Sonderlösungen bei der brandschutztechnischen Bewertung von Konstruktionsdetails

Special‐purpose solutions in the fire‐protective evaluation of construction details Very often components or construction details in existing buildings but also in new buildings cannot be evaluated with regard to its fire resistance ability considering established technical building regulations. There are no regulations for the evaluation of such components or construction details as these specific construction details have not been evaluated by a certified test authority. However, these components and construction details very often can be classified in fire resistance classes e. g. by evaluating fire tests, with regard to DIN 4102‐4, on the basis of similar proof of usability or only by pragmatic considerations. Since introducing the technical approval of the fire protection Eurocodes more often engineering methods of fire protection are used based on these Eurocodes by using temperature assessment in order to secure the evaluation results. Within this essay we show methods and ways of fire‐protective evaluation for components and construction details. The approach of proof including dimensions of possible upgrade measurements if necessary are being illustrated by examples of use out of practical experience. At the same time different materials such as steel, concrete and wood will be treated with different fire‐proof products. The essay is to explain ways of evaluation of components and construction details involving fire‐proof requirements including upgrade measurements also especially for existing buildings.     

Krämerbrücke in Erfurt — Bauwerksgeschichte und Instandsetzung der Gewölbetragkonstruktion in den Jahren 1985/86

Brücken zu bauen und instandzuhalten war zu allen Zeiten eine Herausforderung für Baumeister, Ingenieure und Architekten. Der vorliegende Beitrag soll nach einem kurzen Blick auf die Geschichte des Brückenbaus im Allgemeinen und die der Krämerbrücke im Speziellen, die grundhafte Instandsetzung der Gewölbetragkonstruktion in den Jahren 1985/86 in Erinnerung bringen, ohne die die Krämerbrücke aus dem heutigen Stadtbild sicherlich bereits verschwunden wäre. Krämer Bridge in Erfurt — History of the structure and restoration of the arch supports in 1985/86. Building and repairing bridges has always been a challenge for builders, engineers and architects. This report is designed to provide a glimpse of the history of bridge building in general and that of the Krämer Bridge in particular and recall the fundamental repair work on the arch supports that took place in 1985/86. Without this work, the Krämer Bridge would certainly have disappeared from the current cityscape.     

Deutsche Nationalbibliothek 4. Erweiterungsbau in Leipzig – Besonderheiten bei der Unterfangung und der Bestandssicherung

Derzeit entsteht der 4. Erweiterungsbau der Deutschen Nationalbibliothek in Leipzig. Der neue Baukörper grenzt bereichsweise an die Bestandsgebäude und wurde 6 bis 8 m unterhalb der bestehenden Fundamente gegründet. Der setzungsempfindliche Baugrund infolge eines 4 m mächtigen Kohleflözes musste in der Planung besonders berücksichtigt werden. Um die Bestandsgebäude gegen Setzungen, Rissbildungen und Schiefstellungen zu schützen, wurden außergewöhnliche Sicherungsmaßnahmen realisiert: –·Zusammenspannen der Gebäude mittels Anordnung von Zugstäben –·Auskreuzung gefährdeter Bereiche durch Holz‐Fachwerkverbände –·Anwendung einer besonderen Technologie der HDI‐Unterfangung. Mit diesen Maßnahmen konnten ungleichmäßige Setzungen und Rissbildungen weitestgehend vermieden werden. The German National Library in Leipzig – 4^th extension – Special features of the underpinning and safety measures of inventory. At present the 4^th extension of the German National Library in Leipzig is under construction. The new building is near the existing buildings and was founded in 6 to 8 m below the existing foundations. The ground is liable to subsidence due to a 4 m thick coal seam. This had to be specially considered in the planning. To protect the existing buildings against settlements, cracking and misalignment extraordinary safety measures were implemented: –·tensioning arrangement of buildings by means of tension bars –·strengthening of vulnerable areas by timber trussed bond –·using a special technology of grouted underpinning With these measures, non‐uniform settlements and cracks could be largely avoided.